ooooh, I see what you did there! brilliant construction method for the disk segment. hmm debating on weather to reveal it or not... the width of the stripe segments on the sticker-wrap was really throwing off my perception of how you built it at first Also, the clamp/grill with tiny angle piece was a brilliant move for the front of the warp engine nacells! is the grey hose the rubber kind? and is it attached by use of fireman nozzles?

As for strickers, I just print them on transparent sticker paper. It is available for laser printers and should not cost more than a handful of cents per sheet. Ask in local paperworks store, or a store with printing accessories.

Design of the stickers, colours and scaling... thats all a matter of experience